Internal-combustion engine.



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INTERNAL COMBUSTION ENGINE APPLICATION FILED APR. I8, |916.

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To all whom timmy concern.' c

Be it known that I, EARL E. KIMBALL, a citizen of the United States,residing at Brookline, county of Norfolk, Sta-te of Massachusetts, haveinvented anlmpr ovement in Internal-Combustion Engines, of which thefollowing description, in connection with the accompanying drawings, isaspecification,'like characters on the drawings representing like parts.1

This invention relates tointernal combustion engines and has foritsobject to provide an engine with a slow-rotating cam shaft.constructed. to provide the desirable quick-openimg` and closing of thevalves notwithstanding the relatively-slow rotary movement thereof. l L

The ordinary founcycle internal combus tion engine is provided `with acam shaft by which the valves are opened and closed and which is gearedto the `crank shaft by a twoto-one gearing sothat the cam shaft moves atone-half the speed of the crank shaft. The cam shaft `is provided withcams so constructed that each rotation of the cam shaft will open eachvalve once. It is desirable that the valves should open and close with aquick movement and the cams that are used on the cam shaft for operatingthe valves are shaped to give as quick an opening and closing movementas possible, but when the engine is running very rapidly and the camshaft has a correspondingly rapid speedof rotation,the more or lessabrupt cams on the cam shaft are apt to cause the valves to jumpvwhichresults in an uneven operation of the engine. 1 obviate this byproviding a multiple cam for each valve which is constructed to securethe opening and closing of the valve a plurality of times during eachrotation of the cam and l interpose a train of gearing between the crankshaft and the cam shaft by which the cam shaft will be rotated at a verymuch slower speed than the crank shaft. By this means a slow-moving camis provided which nevertheless will give the requisite quick-opening andclosing movement to the valve.

ln order to give an understanding of my invention, l have illustrated inthe drawings a selected embodiment thereof which will now be described,after which the novel features will be pointed out in the appendedclaim.

Figure 1 of the drawings is a vertical sectional view through aninternal combustion Specification of Letters Patent.

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Application le. April 18, 1916. SeralNo. 92,005.

engine embodying kmy inventionwith a por-` tion of the crank casingshown in elevation; .Eiga 2 is a section on the line linei2-2, Eig- 1;

Fig. is a valve stem.

Fig. 4 is a section on the line 4, Fig. 3. j IV have shown at 1 aninternal combustion engine having the cylinder 2 in which `opcrates thepiston 3, saidpiston being connected by a connecting rod 4 to the crank6 ofthe crank shaft 5. The cranks operate in the usual crank casing 7. 8is one of the valves (either the inlet valveorthe outlet valve)controlling the port 41 tothe cylinder. This valve is herein shown as apiston valve provided with communication is established between `themanifold 43 and the port 41.` The valve is` for each cylinder areactuated from a cam shaft 10 by suitable cam mechanism which embodies myinvention. The cams which l have herein illustrated for the `valves areshown at 11 and these are in the nature of multiple cams, that is, eachcam is provided with a plurality o-f cam projections 12, each one ofwhich acts on the valve stem to open the valve as the cam is rotated. lnthe illustrated embodiment of my invention the cam 11 has twelve suchcam projections 12 so that upon each rotation of the cam the valve 8will be operated twelve times. Each cam projection is provided with theabrupt cam face 13 which acts on the toe or dog' 14 at the end of thevalve stem thereby to raise the valve as the cam rotates anti-clockwiseFig. 1. Each cam projection is also provided with the radially-extendingface 15 so that as soon as the cam projection has passed the toe 14, thevalve can close quickly.

Any suitable gearing may be employed to rotate the cam shaft 10 at theproper speed relative to that of the crank shaft which is necessary tosecure the correct timing of the valve action. Where the cam member 12has twelve cam projections, then it will be necessary to rotate the camshaft once only during each twenty-four rotations of the crank shaft.The gearing herein shown for connecting the crank shaftto the cam shaftcomprises a bevel gear 16 fast on daan `View of the and vor the a port42 by which.`

construction and form no Vpart of my present invention The valves toVturn lbackwardly 4in the fork 23.

they cani shaftl meshing suitable bearings 19 carried by the crankcasing 7. This shaft 18 has a Vworm wheel 20 thereon which meshes withla worm 21 fast yon the end of the crank shaftl 5. This worin gearingprovides a simple device for ldriving the cam shaft from the crank shaftat the proper reduced speed. The toe 14 willvbe pref the lvalve stein!)Vso as topermit the cam 1l whenv in the position shown in Fig. 1 withoutinjuring the valve rod in case the engine back lires.' yThe lower end ofthe valve stem 9 is shown as forked,

as at 23, and the toe 14 is provided with an extension 24 that isreceived between the arrnsof the fork 23. l This toe memberv 14 issecured to a pin 22 which is journaled in thearms of the fork 24 andsaid toe Inemer is provided with the inclined face '25 which engages aninclined face 26 formed A spring-27 acts to hold the toe member yielwith the 'gear 17 Y Afast on a cross shaft 18 ythat is journaled inerably.V veldinglyl connected toA 14 will keep the inclined face 25against the inclined face 26 so that the toe and valve stem will actasarigid member in opening the valve. If, however, the engine should backreand the cam should be rotated backwardly, the toe 14 will yield, thuspreventing any damage from occurring. By means of this construction itis possible to use a slow-moving cam shaft which will eliminate anypossibility of the valve jumping and yet it is possible to have thevalves opened and closed quickly.

y improved engine is especially useful in operating automobiles, airships and other devices where a high speed is desirable.

I claim:

In an internal combustion combination with a cylinder, of a pistontherein, a crank shaft to which the piston is connected, a valve havinga valve stern, a'vtoe pivoted to the valvey stem and'capable of swingingbackwardly about its pivot, a cam shaft, a cam element thereon having aplurality of projections to engage said toe, and thereby actuate saidvalve, a worm on the crank shaft, and a countershaft geared to the camshaft and having a Worm wheel thereon ymeshing with said worm.

In testimony whereof, l have signed my name to this specification.

EARL F. KIMBALL.

engine, the

Gopies of this patientrmay `be obtained for five cents each, byaddressing the Commissioner of Patents.

- y v f Washington, D. C.

